Eleven states do not require families to register with any school district or state agency that they are teaching their children at home, according to the Coalition for Responsible Home Education, a nonprofit group that is pushing for more accountability in home schooling. Fourteen states do not specify any subjects that families must teach, and only nine states require that parents have at least a high school diploma or equivalent in order to teach their children. In half the states, children who are taught at home never have to take a standardized test or be subject to any sort of formal outside assessment.